Refrigerator lighting

ABSTRACT

A refrigerator having functions to improve visibility in a space inside the refrigerator 1 and to have foods inside the refrigerator looking appetizing. Conventional refrigerators have only one, or at the most 2 lamps on an innermost wall surface of a refrigerator chamber, which makes it difficult to see foods and indications on the foods. The refrigerator of the invention overcomes this problem by providing interconnection-type lamps 6 on a front end of a refrigerator ceiling surface 4 and/or a front end of an under surface of a tray 5 over the entire width of the ceiling or the tray, and a reflection/shielding plates on front sides of the lamps 6. This arrangement offers enhanced utility of household and industrial refrigerators.

TECHNICAL FIELD

The present invention relates to a refrigerator having a lightingfunction which illuminates spaces inside a chilling chamber and afreezing chamber in the refrigerator so as to improve visibility of thecontents of the refrigerator and to make the contents appetizing.

BACKGROUND ART

Hitherto, the interior of a refrigerator has been lighted with one, ortwo at the most, lamps or bulbs of small luminance secured to theinnermost wall of the refrigerator to make the contents of therefrigerator visually recognizable.

Lighting of the interior of a refrigerator has to be made in such a wayas to meet the requirements for better visibility inside therefrigerator and for improved working conditions or environment insidethe refrigerator. More specifically, in regard to the first requirement,it is necessary that the lighting be done in such a way as to facilitatevarious kinds of work to be done in the refrigerator, e.g., finding offoods, putting foods into and out of the refrigerator, and reading ofthe labels on the foods, while avoiding dazzling. As to the secondrequirement, the lighting must be done in such a way as to give animpression that the foods as the contents of the refrigerator arecolorful and appetizing, as well as an impression that the interior ofthe refrigerator is neat and clean. The type and location of the lightsource have to be selected to satisfy the above-described lightingrequirements.

Conventionally, lighting inside a refrigerator relies upon a lightsource of a low luminance, e.g., a sewing machine lamp of 10 W or so,embedded in the innermost wall of the refrigerator, due to variousrestrictions in regard to arrangement of the cooling system and othercomponents inside the refrigerator, as well as insulation of such systemand components from the heat. Consequently, the known lighting systemhas posed problems such as dazzling, poor visibility of the foods andcontents, difficulty in reading labels and giving impressions that thefoods are not appetizing and the interior of the refrigerator is gloomyand dirty.

Usually, an illuminating lamp used in a refrigerator is partially orwholly made of a material having light-diffusing transmissioncharacteristics, e.g., acrylic resin. In addition, no light is availablefor illuminating the inner wall surface of the refrigerator door, sothat the shelves on the inner surface of the refrigerator door arecompletely in darkness when a room in which the refrigerator isinstalled is not lighted. The light from the aforesaid illuminating lampis directed from the innermost end of the refrigerator towards the user,so that the interior of the refrigerator may be darkened when foods aredisposed at such positions that they interrupt the light from the lamp.For these reasons, the users are often obliged to bring food out of therefrigerator to see it under an external lighting. Known lighting in theinterior of refrigerator is not considered to enable the user to haveany sense concerning the depth of-the refrigerator. In addition, theuser's eyes inevitably see both the bright spot (illuminating lamp) anddark portions, so that the user tends to be dazzled and annoyed.

An object of the present invention is to ensure brightness of a levelhigh enough to facilitate various kinds of work to be done inside arefrigerator, while avoiding dazzling of a light source and giving suchimpressions that the foods are colorful and appetizing and the interiorof the refrigerator is neat and clean, thereby overcoming theabove-described problems of the prior art.

Another object of the present invention is to make it possible toilluminate also the shelves on the inner surface of the refrigeratordoor, while providing lighting in good balance with the environmentalbrightness, thus further eliminating visual dazzling of the user.

DISCLOSURE OF THE INVENTION

(1) According to the invention, there is provided a refrigeratorcomprising an interconnected lamp extending over the entire length, fromthe left to the right end, of the ceiling of the refrigerator and/or theunder face of a tray in the refrigerator, and a reflective-shieldingplate for reflecting and shielding the light of the interconnected lamp.

In a specific form of the invention, there is provided a refrigeratorwhich employs an illuminating lamp the power spectrum of which issuppressed in the wavelength band of 570 to 590 nm relative to that ofordinary light.

The arrangement set forth above ensures brightness of a level highenough to facilitate various kinds of work to be done inside therefrigerator and gives impressions that the foods are fresh andappetizing and the interior of the refrigerator is clean, while avoidingdazzling.

(2) The present invention also provides a refrigerator in whichilluminating lamps are provided on various surfaces including the innerwall surface of the refrigerator door, while suitably modulating theratio of luminance between these surfaces by the lamps.

This arrangement enables the user to feel more spacious than the realspace inside the refrigerator and to easily recognize the foods becausethe front surfaces of the foods are more sufficiently lighted than theinner wall surfaces of the refrigerator. Furthermore, the user isrelieved from visual dazzling and annoyance because the light from thelight source (lamp) of high luminance does not directly enter the user'seyes.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1a is a schematic front elevational view of an embodiment of arefrigerator in accordance with the present invention, in a state inwhich a door has been opened; FIG. 1b is a schematic sectional sideelevational view of the refrigerator with the door removed; FIG. 2 is afront elevational view of an interconnected lamp used in therefrigerator; and FIG. 3 is a schematic front elevational view of anessential portion of another embodiment of a refrigerator in accordancewith the present invention, in a state in which a door has been opened.

BEST MODE FOR CARRYING OUT THE INVENTION

Preferred embodiments of the present invention will be described withreference to the accompanying drawings.

(Embodiment 1)

Referring to FIGS. 1a and 1b, the reference numeral 1 denotes arefrigerator, 2 denotes doors of the refrigerator, 3 denotes aninnermost wall surface of the refrigerator 1, 4 denotes ceiling surfacesof the refrigerator 1, 5 denotes trays in the refrigerator 1, 6 denotesinterconnection-type lamps as an illuminating light source provided onthe front ends of the ceiling surfaces 4 and/or the front ends of thelower faces of the trays 5, and 7 denotes reflective-shielding plateswhich serve to reflect the light from the interconnected lamps 6 towardsthe innermost end of the refrigerator 1 while shielding the front orentrance side of the refrigerator 1 from the light of the lamps 6.

The innermost wall surface 3 and the ceiling surfaces 4 are made of amaterial having a high reflection/diffusion characteristic so as not tomake reflect images dazzling. The interconnected lamps 6 have a lengthwhich is substantially the same as the breadth of the space inside therefrigerator 1. The reflective-shielding plates 7 provide such ashielding function as to prevent the light of the lamps 6 from beingdirectly seen by the user. Dazzling can effectively be suppressed if theluminance of the lamps 6 through the reflecting plates 7 can be reducedto a level of 1100 cd/m² or less when the lamps 6 are turned on.

The arrangement may be such that a diffusion plate is used in place ofthe reflective-shielding plates 7 so as to cover the lamps 6 to providea transmitted light. In such a case, dazzling can effectively besuppressed if the luminance of the lamps 6 through the diffusion plate 7can be reduced to a level of 1100 cd/m² or less.

FIG. 2 illustrates an example of the interconnected lamp 6. The lamp 6has an outer bulb 8a and a plurality of inner bulbs 8b in the outer bulb8a. The outer bulb 8a is hermetically closed at the opposite ends by endpieces 9. Each inner bulb 8b accommodates a tungsten wire 10 and theinterior of the bulb 8b is kept under a vacuum to prevent the tungstenwire 10 from burning. Each of the inner bulbs 8b can be regarded asbeing equivalent to a single lamp bulb conventionally employed for theillumination of the refrigerator interior. Thus, the series of internalbulbs 8b provides the same effect as that produced when a series ofindependent small lamps are lit on. Connecting a multiplicity of smallbulbs in series undesirably requires a large number of steps in theassembly process and is not preferred from the view point of safety. Incontrast, the interconnected lamp 6 used in the present invention,however, can be installed in a single step. In addition, by varying thenature of the outer bulb 8, it is possible to obtain the same effect asthat produced when a multiplicity of light sources are changed at once.When it is desirable to give an impression that the foods and foodmaterials inside the refrigerator 1 are appetizing, it is preferred touse, as the outer bulb 8a, a bulb which absorbs power spectrum of awavelength in the region of 570 to 590 nm. An evaluating experiment hasbeen conducted by employing lamps having bulbs which absorb powerspectrum of a wavelength in various wavelength regions to confirm thatit is most effective to improve deliciousness of foods that the lightcomponent of wavelength region of 570 to 590 nm is reduced by absorptionto a level lower than that in ordinary lamps.

A description will now be given of the functions of the illustratedembodiment of the refrigerator in accordance with the present invention.The light emitted from the interconnected lamps 6 is reflected by thereflective-shielding plate 7 towards the innermost end of therefrigerator 1, so that the user is not dazzled because the light fromthe lamps 6 is not directly seen by the user. The interconnected lamp 6is a continuous linear lamp which extends from one end to the other inthe space inside the refrigerator 1, so that it provides greater lightdiffusion and uniformity of light distribution, thus avoiding localshading by foods or user's hands, thus realizing better illuminatingconditions with improved visibility as compared with theconventionally-used point source.

The interconnected lamp 6 constitutes an interconnection-type lightsource to enhance luster and shine of the foods and food materials suchas meats and vegetables to make them more appetizing. In particular,food looks highly attractive and appetizing when lamps capable ofabsorbing power spectrum of 570 to 590 nm are used as the outer bulbs 8aof the interconnection-type lamps 6. The interconnection-type lamps 6are preferably installed on the front sides of the ceilings 4 and/or thefront ends of the under surfaces of the trays 5 as shown in FIG. 1, sothat the positional relationship between the food and the light sourcesis not such as to cause a phenomenon called as "silhouette phenomenon"in the field of photography, thus facilitating seeing the food whileavoiding dazzling by the light sources.

Thus, the illustrated embodiment makes it possible to improve visibilityof the contents in the chilling chamber or freezing chamber in arefrigerator and to have the food looking more appetizing.

(Embodiment 2)

FIG. 3 is a schematic front elevational view of another preferredembodiment of the refrigerator in accordance with the present inventionwith both refrigerator doors opened, showing also an electric circuit.In the drawing, the reference numeral 11 denotes a refrigerator, 12denotes a floor surface of the refrigerator 11; 13 denotes a ceilingsurface; 14 denotes an innermost wall surface; 15a, 15b denote surfacesof both side walls; 16a, 16b denote inner surfaces of the refrigerator11 doors; 17 denotes food to be chilled in the refrigerator 11; 18denotes an illuminating lamp which is disposed on the front end of thefloor surface 12 so as to extend from the right to the left; 19 denotesan illuminating lamp secured to the innermost end of the ceiling surface13 so as to extend from the right to the left; 20 denotes anilluminating lamp secured to an upper portion of the innermost wallsurface 14 to extend from the right to the left; 21a, 21b denoteilluminating lamps disposed vertically on the front ends of the sidewall surfaces 15a, 15b; 22a, 22b denote illuminating lamps secured toupper portions of the door inner surfaces 16a, 16b so as to extend inthe widthwise direction of the door; 23 denotes an illuminating lampsecured to the front end of the ceiling surface 13 so as to illuminatefoods 17; 24 denotes a background surface of the refrigerator 11; 25denotes an illuminating lamp disposed externally of the refrigerator 11and illuminating the background surface 24 of the refrigerator 11; 26denotes a power supply for the lamps mentioned above; and 27 denotes alight control which is interconnected between the power supply 26 andthe respective illuminating lamps.

The refrigerator floor surface 12, the refrigerator ceiling surface 13,the refrigerator innermost wall surface 14, the refrigerator side wallsurfaces 15a, 15b and the inner surfaces 16a, 16b of the refrigeratordoor define a cubic or three-dimensional internal space of therefrigerator 11. The refrigerator 11 may have a single door and hence asingle inner surface of refrigerator door. As explained above, thelighting control 27 is connected between the illuminating lamps 18, 19,20, 21a, 21b, 22a, 22b, 23 and 25 and the power supply 26 to effectlighting and control of the respective illuminating lamps independently.The illuminating lamp 18 uniformly illuminates the refrigerator floorsurface 12. The illuminating lamp 19 uniformly illuminates therefrigerator ceiling surface 13. The illuminating lamp 20 uniformlyilluminates the refrigerator inner wall surface 14. Similarly, theilluminating lamps 21a, 21b; 22a, 22b; and 25 uniformly illuminate theinner side wall surfaces 15a, 15b, the inner wall surfaces 16a, 16b ofthe refrigerator doors, and the back side 24 of the refrigerator,respectively.

In order to clarify the relationships between the luminance at variouspoints in the refrigerator and an impression of a spaciousness insidethe refrigerator, a subjective evaluation experiment with respect to aspace sense inside the refrigerator was conducted by independentlyvarying the luminance on the background surface 24 and the luminance onthe refrigerator floor surface 12, the refrigerator ceiling surface 13,the refrigerator innermost wall surface 14, the inner side wall surfaces15a, 15b, the inner surfaces 16a, 16b of the refrigerator doors,respectively.

More specifically, the experiment was conducted under five differentilluminating conditions, in which a ratio L₁ /L₂ assumed 1/1, 2/1, 3/1,4/1 and 5/1, where L₁ represents the luminance on the refrigerator floorsurface 12, refrigerator ceiling surface 13, refrigerator innermost wallsurface 14, the inner side wall surfaces 15a, 15b and the inner surfaces16a, 16b of the refrigerator doors, while L₂ represents the luminance onthe background surface 24. The experimental result was submitted to fiveobservers for evaluation of an impression of a spaciousness inside therefrigerator. The test was repeated three times employing five panelists

As a result, it has been confirmed that an impression of a spaciousnessis obtained when the ratio (L₁ /L₂) between the luminance L₁ and L₂ isset to be 3 or greater.

As a result of the experiment, the user who has opened the refrigeratordoors can feel more spacious than the real space inside therefrigerator, when the light control 27 is so set that the ratio L₁ /L₂,of the luminance L₁ of the refrigerator floor surface 12, refrigeratorceiling surface 13, refrigerator innermost wall surface 14, the innerside wall surfaces 15a, 15b and the inner surfaces 16a, 16b of therefrigerator doors to the luminance L₂ on the background 24 of therefrigerator is 3 or greater.

In order to find a condition of luminance distribution which makes foodsin the refrigerator easy to see, a visibility evaluation experiment withrespect to the interior of the refrigerator was conducted byindependently varying the luminance L₃ on the food 17 illuminated by theilluminating lamp 23 and the luminance L₁ on the refrigerator floorsurface 12, refrigerator ceiling surface 13, refrigerator innermost wallsurface 14, the inner side wall surfaces 15a, 15b, and the innersurfaces 16a, 16b of the refrigerator doors.

More specifically, the experiment was conducted under five differentilluminating conditions, in which a ratio L₁ /L₃ assumed 1/1, 2/1, 1/3,1/4 and 1/5, where L₁ represents the luminance on the refrigerator floorsurface 12, refrigerator ceiling surface 13, refrigerator innermost wallsurface 14, the inner side wall surfaces 15a, 15b and the inner surfaces16a, 16b of the refrigerator doors, while L₃ represents the luminance L₃on the food 17 illuminated by the illuminating lamp 23. Five observersparticipated in the experiment and the test was repeated three times.

As a result, it has been found that the front side of the food 17 isvisible rather than forming a silhouette when the ratio (L₁ /L₃) betweenthe luminance levels L₁ and L₃ is set to be 1/3 or smaller.

On the basis of the above-mentioned experiment, the front side of thefood is visible rather than forming a silhouette, when the light control27 is so set that the ratio L₁ /L₃, of the luminance L₁ of therefrigerator floor surface 12, refrigerator ceiling surface 13,refrigerator innermost wall surface 14, the inner side wall surfaces15a, 15b, the inner surfaces 16a, 16b of the refrigerator doors to theluminance L₃ on the front side of the food illuminated by the lamp 23 is1/3 or smaller. It has been found also that the depth of therefrigerator 11 can be sensed when the lighting control 27 is so set asto satisfy the condition of X₁ ≧X₂ ≧X₃ ≧X₄, where X₁ represents theluminance of the refrigerator innermost wall surface 14, X₂ representsthe luminance of the refrigerator floor surface 12, refrigerator ceilingsurface 13 and the refrigerator sidewall inner surfaces 15a, 15b, X₃represents the luminance of the refrigerator door inner surfaces 16a,16b, and X₄ represents the luminance of the background surface 24.

The above-mentioned ratios L₁ /L₂ and L₁ /L₃ may be controlled by meansother than the lighting control. For example, the lamps may be simplyon-off controlled and the ratios of the luminance may be set to fallwithin the above-mentioned ranges, as by, for example, varying thenumbers of the lamps, positions of the lamps or orientations of thelamps.

The lamps employed in this embodiment also are encased or shielded suchthat light from these lamps can not be directly seen by the user, andthe luminance levels of the respective surfaces are set to be lower than1100 cd/m², thereby preventing dazzling. It is also possible to use aluminescent panel such as EL panels as the refrigerator walls, insteadof the illuminating lamps.

As will be understood from the foregoing description, according to thepresent invention, the front side of the food inside the refrigerator ismade brighter than the inner wall surfaces of the refrigerator, so thatthe foods are clearly visible and bright. In addition, the user can feelmore spacious than the real space inside the refrigerator, because theinner wall surfaces of the refrigerator is made brighter than thebackground of the refrigerator. In particular, the user can feel morespacious than the real space inside the refrigerator. Furthermore,dazzling and visual annoyance are avoided because light from theilluminating lamps of high luminance levels is out of the visual fieldof the user.

INDUSTRIAL APPLICABILITY

As will be understood from the foregoing description, the refrigeratorin accordance with the present invention improves visibility inside therefrigerator owing to the provision of illuminating lamps which arebrighter than those used in known refrigerators and can have foodslooking delicious. In addition, the user can sense the lateral anddepthwise extensions of the space inside the refrigerator, because theinner wall surfaces of the refrigerator are brighter than the backgroundof the refrigerator. Thus, the present invention offers satisfaction tothe users of household or industrial refrigerators.

We claim:
 1. A refrigerator comprising: interconnection-type lamp meansextending from the right to the left over the entire width of a spaceinside the refrigerator and provided on at least one of the front end ofthe ceiling or the front end of the under surface of a tray; andreflection/shielding plate means provided on the front side of saidinterconnection-type lamp means so as to reflect light towards theinnermost end of said space while shielding the front end of therefrigerator from said light.
 2. A lamp for a refrigerator, said lampcomprising:illuminating lamp means for producing light having a powerspectrum; and means for lowering said power spectrum at a wavelengthregion of from 570 to 590 nm.
 3. A lamp for a refrigerator according toclaim 2, wherein said means for lowering comprises an outer bulb whichis disposed around said illuminating lamp means and which absorbs partof said light at said wavelength region.
 4. A refrigerator comprising:arefrigerator door having an inner surface; a refrigerator compartmenthaving a refrigerator floor surface, a refrigerator ceiling surface, aninnermost wall, and refrigerator sidewall inner surfaces; anilluminating lamp A for illuminating a whole area of said inner surfaceof said refrigerator door; an illuminating lamp B for illuminating awhole area of said refrigerator floor surface; an illuminating lamp Cfor illuminating a whole area of said refrigerator ceiling surface; anilluminating lamp D for illuminating a whole area of said innermost wallof the refrigerator; illuminating lamps E for illuminating whole areasof said refrigerator sidewall inner surfaces; an illuminating lamp F forilluminating a background surface outside said refrigerator; a powersupply source for supplying electrical power to said illuminating lampsA to F; and a lighting control connected between said illuminating lampsA to F and said power supply source; wherein, when the refrigerator doorhas been opened, said illuminating lamps provide such illumination thata ratio (L₁ /L₂) of luminance L₁ of a region defined by the refrigeratordoor inner surface, refrigerator floor surface, refrigerator ceilingsurface and the refrigerator side wall inner surfaces to luminance L₂ ofsaid background surface is 3 or greater.
 5. A refrigerator according toclaim 4, wherein said illuminating lamps A to E provide suchillumination as to meet a condition of X₁ ≧X₂ ≧X₃ ≧X₄, where X₁represents luminance of the refrigerator innermost wall surface, X₂represents luminance of the refrigerator floor surface, refrigeratorceiling surface and the refrigerator sidewall inner surfaces, X₃represents luminance of the refrigerator door inner surface, and X₄represents luminance of the background surface.
 6. A refrigeratoraccording to claim 4, wherein, when said illuminating lamps are turnedon, luminance levels of the refrigerator door inner surface,refrigerator floor surface, refrigerator ceiling surface, refrigeratorinnermost wall surface, refrigerator side wall inner surfaces and therefrigerator background surface are lower than 1100 cd/m².
 7. Arefrigerator according to claim 4, wherein light-emitting portions ofall said illuminating lamps except for said illuminating lamp F arehidden outside a visible field of the user.
 8. A refrigerator accordingto claim 5, wherein light-emitting portions of all said illuminatinglamps except for said illuminating lamp F are hidden outside a visiblefield of the user.
 9. A refrigerator comprising:at least onerefrigerator tray; at least one refrigerator door; and an illuminatinglamp provided on each said at least one refrigerator tray so as toilluminate a front side of food lying on said each of said at least onerefrigerator tray at least from the front end of said each of said atleast one refrigerator tray; wherein said illuminating lamps providesuch illumination that a ratio (L₁ /L₃) of luminance L₁ of a regiondefined by a refrigerator door inner surface, refrigerator floorsurface, refrigerator ceiling surface and refrigerator side wall innersurfaces to luminance L₃ of the front side of said food lying on saideach of said at least one refrigerator tray is 1/3 or smaller when theat least one refrigerator door has been opened.
 10. A refrigeratorcomprising:at least one refrigerator door having an inner surface; arefrigerator compartment having a refrigerator floor surface, arefrigerator ceiling surface, an innermost wall, and refrigeratorsidewall inner surfaces; at least one refrigerator tray; an illuminatinglamp A for illuminating a whole area of said inner surface of said atleast one refrigerator door; an illuminating lamp B for illuminating awhole area of said refrigerator floor surface; an illuminating lamp Cfor illuminating a whole area of said refrigerator ceiling surface; anilluminating lamp D for illuminating a whole area of said innermost wallof the refrigerator; illuminating lamps E for illuminating whole areasof said refrigerator sidewall inner surfaces; an illuminating lamp F forilluminating a background surface outside said refrigerator; and anilluminating lamp G provided on each of said at least one refrigeratortray for illuminating a front side of food lying on said each of said atleast one refrigerator tray at least from the front end of said each ofsaid at least one refrigerator tray; wherein said illuminating lampsprovide such illumination that a ratio (L₁ /L₃) of luminance L₁ of aregion defined by the inner surface of said at least one refrigeratordoor, refrigerator floor surface, refrigerator ceiling surface and therefrigerator side wall inner surfaces to luminance L₃ of the front sideof said food lying on said each of said at least one refrigerator trayis 1/3 or smaller when the at least one refrigerator door has beenopened.
 11. A refrigerator according to claim 10, wherein saidilluminating lamps A to E provide such illumination as to meet acondition of X₁ ≧X₂ ≧X₃ ≧X₄, where X₁ represents luminance of therefrigerator innermost wall surface, X₂ represents luminance of therefrigerator floor surface, refrigerator ceiling surface and therefrigerator sidewall inner surfaces, X₃ represents luminance of therefrigerator door inner surface, and X₄ represents luminance of thebackground surface.
 12. A refrigerator according to claim 10, wherein,when said each illuminating lamps is lit on, luminance levels of therefrigerator door inner surface, refrigerator floor surface,refrigerator ceiling surface, refrigerator innermost wall surface,refrigerator side wall inner surfaces and the refrigerator backgroundsurface are lower than 1100 cd/m².
 13. A refrigerator according to claim10, wherein light-emitting portions of all said illuminating lampsexcept for said illuminating lamp F are hidden outside the visible fieldof the user.
 14. A refrigerator according to claim 11, whereinlight-emitting portions of all said illuminating lamps except for saidilluminating lamp F are hidden outside the visible field of the user.